Field of the Disclosure
The present disclosure relates to a display device, and more particularly, to a light blocking device, a method of manufacturing the same, and a transparent display device including the same, which realize a light transmitting mode and a light blocking mode.
Description of the Background
Recently, as the advent of the information age, the display field of processing and displaying a massive amount of information is rapidly advancing, and correspondingly, various flat panel display (FPD) devices have been developed and are attracting much attention.
Examples of the FPD devices include LCD devices, plasma display panel (PDP) devices, field emission display (FED) devices, electroluminescence display (ELD) devices, organic light emitting diode (OLED) display devices, etc. The FPD devices have good performances such as thinness, lightness, and low consumption power, and thus, the application fields of the FPD devices are continuously increasing. Particularly, in most electronic devices or mobile devices, the FPD devices are used as a type of user interface.
Moreover, transparent display devices which enable a user to look at a background or an object located behind the transparent display devices are being actively researched recently.
The transparent display devices are advantageous in space availability, interior, and design and may be applied to various fields. The transparent display devices realize an information recognition function, an information processing function, and an information display function by using a transparent electronic device, thereby solving the spatial limitation and visual limitation of electronic devices. For example, a transparent display device may be applied to windows of buildings or vehicles and thus may be implemented as a smart window which allows a background to be seen or displays an image.
Some transparent display devices including an LCD device may be implemented by applying an edge type backlight, but is very low in transmittance. Also, transparent display devices using LCD technology has a problem where transparency is reduced due to a polarizer used for realizing black, and moreover, has inferiority in outdoor visibility.
Furthermore, transparent display devices including an organic light emitting diode (OLED) have high power consumption in comparison with LCD devices and are difficult to realize true black. Also, in the transparent display devices including the OLED, a contrast ratio is not changed in a dark environment but is reduced in a normal environment having light.
In order to realize a light transmitting mode and a light blocking mode, therefore, a method using a polymer dispersed liquid crystal (PLDC) has been proposed for a light blocking device applied to the transparent display devices including the OLED. In a method of producing the PDLC, a liquid crystal is mixed with a monomer, and then, by converting the monomer into a polymer through a ultraviolet (UV) curing, the liquid crystal is converted into a droplet in the polymer, thereby producing the PDLC.
When an electric field is applied to the PDLC, the alignment of the liquid crystal located in the polymer is changed. Therefore, the PDLC may scatter or transmit light incident from the outside. That is, a device using the PDLC can scatter or transmit light even without the polarizer, and thus, may be applied as a light blocking device to the transparent display devices.